Hyperloop Freight is a Joke
pedestrianobservations.wordpress.com
pedestrianobservations.wordpress.com
First, no one said that designing this thing in the USA means it has to be deployed in the USA. Countries without common law legal systems get around these unnecessary costs much easier.
Second, if these are seriously the only objections, then thank god we are actually building this thing. I could see complaints if it were some $100 billion publicly funded project, but the fact that less than $1 billion in private capital has already gone so far into demonstrating the technological feasibility of such an innovative transportation mechanism is a huge win.
But in the case of a company raising funding and claiming it wants to build a ton of subsidized infrastructure to service the public, it isn't the case that we should say, "This is better than some more vacuous application of the money." Because it's not at all clear that Hyperloop is actually a good plan to reintroduce high speed rail into America when so many problems keep coming to light about it.
To summarize:
- construction costs are underestimated or completely wrong
- capacity is lower than standard HSR
- Hyperloop claims power usage is higher for HSR than it actually is
- forces aren't adequately accounted for even with canting
- assuming perfect canting the pylons must take the additional force
- the majority of travel time is to/from the station + security screening.
To me, it seems like it's optimizing for the wrong section of the trip.
What makes sense for international air mail doesn't make sense for a four hour journey by truck, especially if that truck can take a container straight from the ship to the city depot without carefully repacking everything, or go door to door with smaller loads.
Highways for example have fairly wide banks which people rarely notice. https://sterlingpearce.files.wordpress.com/2015/02/img_0054....
Elevators are different because you don't spend more than about 1 minute in an elevator.
Remember 1g * 1 second is only ~22mph.
The problem is when it's sustained. That's why people get sick on roller coasters and when doing aerobatics (extreme examples, I know).
Although as the poster mentioned below, a passenger service would gradually rotate the passenger compartment to keep the G-forces vertical, a la a banking aircraft, so all you'd likely notice would be feeling heavier for a few seconds.
See https://pedestrianobservations.wordpress.com/2013/08/13/loop... linked from the original article.
This seems to be the comment in question:
> This is worse than sideways acceleration: track standards for vertical acceleration are tighter than for horizontal acceleration, about 0.5-0.67 m/s^2, one tenth to one seventh what Musk wants to subject his passengers to. It’s not transportation; it’s a barf ride.
I find the statement that vertical acceleration is 'worse than sideways acceleration' to be highly suspect (otherwise why would you bother to bank into turns?) - I would guess that the track standards are for +/- 0.5ms^-2 and mostly target short-period up-and-down bouncing motions rather than smoothly applied upwards acceleration.
At the time of typing this the pessimism has been entirely reasonable and I'd say in the minority, with Xorlev outlining the fundamental issues with Hyperloop (capacity, costs, solving the wrong end of the problem) and KirinDave pointing out how while yes, there are more vacuous ways of spending money, when you're mucking around with other people's dough there's an expectation on return on investment, otherwise it's a charity.
I'd like to see the Hyperloop built just as I'd like all kinds of cool, complex and not necessarily practical technologies develop. But it's not unfair to point out the economic and physical realities that will get in the way of those things.
The factors (i.e. physics) underpinning the economics of freight shipping in all forms are well understood. Can a hyperloop be built? Sure. Is it better than existing intermodal cargo shipment infrastructure? Yes and no. It certainly offers speed, but doomedly at the expense of economies of scale: https://www.usmma.edu/sites/usmma.edu/files/docs/CMA%20Paper...
Here's a thoughtful assessment by Olaf Merk posted last month that draws the same conclusion as the author: http://shippingtoday.eu/musk_maritime/
Bottom line, if you can find enough high value bulk cargo that benefits significantly from high speed transit to only two or three "ports", then hyperloop is your answer. However, that's a very (perhaps nonexistent) niche in the industry.
What we (transport engineering community) need to be expending resources on is: a.) eliminating greenhouse gas emissions, b.) designing a system of transport that scales with global trade demand (vice building 20K+ TEU megaships that can only be served by a few ports and promote trucking congestion in ports). Autonomous shipping, AI implementations in both freight forwarding (the logistics side) and transport control systems themselves, and applications of H2 fuel cells are technologies with great promise.
Positive thinking never solved anything.
Same with the argument about centralization. It's a practical non starter if sticking the load on a truck that just goes to the destination is faster than shifting the load off the truck onto the hyperloop and then back onto a truck.
It might be possible to force it into existence, but it won't be worth it.
Basically expansion and contraction as well as just plain vulnerability of running a vacuum make it extremely difficult to do practically. The phrase he uses, "all the problems of space travel except in a gun barrel" is a pretty accurate description of the issue. Any loss of vacuum will almost guarantee loss of life. No realistic demo has been done even on a small scale as of yet.
I don't think it is unrealistic at all.
Sliders https://www.quora.com/Why-do-oil-pipelines-that-transfer-oil...
Now doing this without bending the long pipe is going to be harder, but you really could design this thing so riders don't notice a magnitude 9 earthquake.
PS: In the end you get into cost benefit designing it to survive an aircraft impact is probably not worth it let alone a nuke, but predictable earthquakes are not that hard.
My wife was PM on an emergency project to replace a 72" main feeding a city that failed.
First, you would get choked flow at the inlet, and if you do the math it actually takes a massive opening to really make a dangerous shockwave.
Eg, if a joint in the tube disconnects and the two halves pull apart, the inlet area is the tube circumference * gap between halves. The two halves would need to separate by the full diameter of the tube (~15 ft) to get full atmospheric pressure going in both sides. A realistic gap of a couple inches to a couple feet is far less scary.
Second, these incidents will be exceptionally rare. Gaps that big are equivalent to a freeway overpass collapsing. It's a total failure scenario, so you see a single digit number of them a year in the US.
Lastly, the speed of sound isn't all that quick on the scale of this thing. It's about 13 miles/min, a fifth of a mile a second.
If you place emergency fill valves (one time use things, dirt cheap, just explosive bolts in the simplest case) you can flood a whole section of the tube with atmosphere in a controlled manner over say 15 seconds, and your shockwave will be largely stopped after 3 miles.
An emergency fill like that would also stop all pods in the region as they hit very high drag, so you don't even need to carry heavy emergency brakes on every vehicle.
2) Because in the case of an explosive recompression there might not be a tube anymore.
I'm not bullish on hyperloop but I see no reason to believe that the engineers can't design a pod capable of not disintegrating in air, or capable of designing a track with a failure mode better than completely falling apart.
The big problem with his air cannon theory is, pipes are not lossless! Friction and viscous interactions between the entering air and the tube wall will slow down that "shock front" to a highway speed wind in only a couple km. So unless it's so close that the pod can't stop in time (and actually derails at the breach), there should be no loss of life.
As far as thermal expansion, that can be solved with sliding interfaces every few hundred meters. The Hyperloop has switched to mag-lev designs for levitation, so the ultra smooth interior is no longer necessary. There will be some air leakage at the joint of course, but this can easily made up by the pumping stations installed at intervals along the track.
The pressure in the Hyperloop was specifically chosen so that simple mechanical vacuum pumps can be used -- no turbomolecular or cryopumps needed. The Hyperloop runs at 1/1000th of an atmosphere. True "vacuum trains" use vacuums at about 1/1,000,000th of an atmosphere, meaning the pumping is about 1000 times harder (not because the pressure difference is meaningfully different, but because you only get 1/1000th as much air per "stroke" or "cycle").
The Large Hadron Collider uses a harder vacuum still (about 1/1,000,000,000,000 of an atmosphere, and yes that's a trillionth of an atmosphere), which is why LordHumungous's experience mentioned earlier isn't terribly applicable. The LHC is doing something a lot harder than the Hyperloop.
Derail a train = put a rock on the tracks.
Plus there is a planned emergency repressurization of the whole tube that would eliminate even that medium speed shock front. Plus a small 10cm diameter bullet hole would imply in less than 1% of the flow of a completely broken tube (a much harder feat to do), per laws of conservation of energy and matter.
As pods travel with 4km or so of separation, at most one pod will be affected. That is much less people than a derailed train.
For example, there was lots of hang-wringing over Fusion power back in the 1970's, about how if the bureaucrats would just give it more funding then it would happen: https://upload.wikimedia.org/wikipedia/commons/a/ab/U.S._his...
I'm not saying any of this tech is without merit, just that it's common to need buy-in from many organizations to make it happen.
This critique, however, raises quite specific physics-related logistical reasons why Hyperloop is a ludicrously impractical solution for most forms of freight and uneconomical for the rest. Things it doesn't mention, even implicitly, include regulation, government and lawyers. Perhaps you'd get more out of these hyperloop criticisms if you read them?
It's not like investors are blind or dumbstruck just because it's an idea from Musk.
They do their due diligence and if they think the plan has potential, they invest.
I'm sure there were countless technical issues and big challenges around airplanes in the initial stages. And cars. And trains. And, you know, every new technology.
Could Hyperloop (One) fail miserably? Sure. Could it succeed? Also.
Let's just wait and see.
Also, whenever there are invested interests of established competition, they usually drum up the PR machine against new ideas, just as a precaution.
Just look at the fascinating history of fridges vs ice box companies for one of countless examples.
The industry as a whole is far more mature now, and paths to monetization are clearer. Competition is high, so is the competence of most VCs and investors.
I'd also place an engineering project like Hyperloop in a whole different space than the typical SV stuff.
Except, as the article points out, it's not actually faster, cheaper, or efficient than competing technologies. Those seem like really fatal flaws.
> Countries without common law legal systems get around these unnecessary costs much easier.
That same logic also applies to the competing technologies. The same magic wand that lets you build a hyperloop for 1/10th what it would cost in the US also lets you build the tracks for HSR for 1/10th what it would cost in the US. You can't compare the cost of building a hyperloop in China to the cost of building HSR in California and get a meaningful answer.
Nobody is saying that the hyperloop is impossible; they're saying that it's a plan to build something objectively worse than high speed rail at prices that seem broadly comparable.
It's flashy and all to say you're going to break all the rules, but you could just as easily do that with conventional means of transportation.
Edit: I worked on the LHC for several years. The challenges of maintaining a closed vacuum pipe that spanned a mere 17 miles were vast and expensive. Musk proposes doing it on an exponentially larger scale without addressing the challenges and pitfalls involved. Until he does so, I cannot take him seriously.
The Alaska Pipeline is certified to operate at 1,180 psi.
It's not a problem, and minor leaks are not a problem, either. A leak that would stop a particle accelerator dead in its tracks will just make a hyperloop operate at slightly lower efficiency. Plus you can always just run the pump (any practical design will doubtless have the pumps running continously to make up for leakage, just as many ships and buildings have continuously-running bilge and sump pumps).
First, part tolerances are not a particularly important issue with engineering of high vacuum systems (sealing is effected by compression of gaskets, usually soft stainless steel gaskets for UHV systems).
Secondly, the difficulties in maintaining a large UHV system is usually related to "outgassing", from multiple surfaces and/or material imperfections, and are rarely due to "a single flaw in one part".
Thirdly, you are using the word "exponentially" wrong, even in the context of your flawed claim which is addressed below.
Finally: "the force on the pipe" is not, in a meaningful sense, proportional to the square of the radius. The forces in the pipe wall are proportional directly to the radius (formula is stress=pressure*radius/thickness), if it was otherwise pipe thickness would grow as the square of diameter and large pressurised pipes would be physically impossible.
Happy to do the math for you when you need it, best to leave it to the experts.
I doubt UHV experience is relevant here though - at 100 torr you can probably get away with simple o-ring seals. And outgassing doesn't matter: even isopropanol has a vapor pressure of only 40 torr.
Edit: The hyperloop design is at ~1 torr, not 100. Still, I'd imagine outgassing is not a huge issue.
The vacuum level required for a particle accelerator (10^-11 torr or something like that) and the one posited for the Hyperloop (0.75 torr) are so far apart that they have virtually nothing in common.
Reminds me of the following quote:
Assholes ARE like opinions - Everyone has one.
You, on the other hand, are overwhelmed by the challenge of maintaining vacuum in a tube that spans a mere 17 miles. At the very least, you should restrain yourself from using language like "...some idea he farted out...".
2) Which Hyperloop is failing? There are at least three groups, and as far as I know, they haven't even got close to testing the system, let alone know if it's a failure or not.
I'm skeptical of the whole concept, but declaring failure at this stage is no less silly than assuming it'll definitively work.
You say 'overwhelmed' but I'll just point out it is built and working, and at almost-perfect vacuum.
one day it might be, and more generally i do hope that we see more progress in the electric car world... but for now tesla only turns a profit as a car company coupled with government incentives. even then, outside of the US (and inside actually) their market share is tiny or zero with very little growth. saying that it doesn't even exist is a very good approximation to reality... if you ignore tech focused news articles and the like at least.
i wouldn't call that a success just yet... as much as we may admire the mission.
Subsidies and protective tariffs are the norm in the auto market.
It would put any car company that didn't get them at a significant disadvantage.
Still quite challenging, but not in the same league, even considering that hyperloop requires way longer tunnels.
I'm no expert either, but that sounds rather hollow..
But Hyperloop is unexplored territory. There isn't billions/trillions of fundamental R&D already done and given away for free by somebody else. I suspect that's going to have an impact.
Now, sure there is a lot of new tech that would be needed. But, less than you might think.
Caltrain with express trains works very well. sfo and oak have trains that go into the airport. caltrains goal of electrification if it ever happens should make SF to SJ a lot faster. trains in the Bay Area are not as bad as you make them out to be.
personally I think high speed rail should go from Santa Clarita to gilroy or south San Jose. once you pass up the Central Valley you can take bart or Caltrain to your final destination
A computer analogy I'd give is to think of freight handling like information communication - the big issues are bandwidth (How much can you send/receive in one shipment) latency (How long does it take to arrive) and throughput (How many shipments can you handle at once).
Hyperloop addresses the latency issue but does little to nothing to address the other two problems
From what I see working in a heavy industry which relies on bulk freight (for import and export). Throughput (i.e Congestion) is the hot issue - we have a rail terminal and a deep water berth (which handles capesized ships). The rail corridor is shared and at times pretty heavily congested we use road trains (b-double trucks) to make up for the shortfall.
Getting from Napa Valley to New York, New York in an hour without sitting in a box in the sun would be a big win.
Unsurprisingly, a lot of the theory for transport networks maps extremely well to computer networks.
Transport is essentially a literal packet switched network. You have routers (depots), routes (roads, rails, etc), packets (in many cases, literally packets), MTUs (twenty foot containers, or truckloads).
Queuing theory equally applies to both as well (and a lot of other physical applications, at university we had an exercise applying it to customer support).
Concerning "barf rides": wouldn't Strong and well-timed anesthetics help?
If you're already a maglev, a tube doesn't add much. Japan's maglev has already reached 600 Km/h. The Shanghai/Transrapid maglev routinely runs at 431 Km/h, and has hit 500 in tests. At those speeds, SF-LA is about an hour. But the track cost is very high.
That's not stopping JR Tokai. The Tokyo to Nagoya maglev line has been under construction for two years now. They're taking the most direct route to get the fastest transit time. There are mountain ranges in the way. They're going straight through them. 90% in tunnel. Completion in 2027. Cost comparable to Twitter's peak market cap. Public support for this is so high that JR is being pushed to build the next section, Nagoya to Osaka, sooner.
With enough money...
It all depends on perspective. If decision maker view the maglev as the 21st century version of the railway that let societies prosper in the 19th and 20th, then it might not be expensive at all because the return is so great and the horizon so long.
Drag power is proportional to the cube of velocity, so drag energy losses over a fixed distance are proportional to the square.
In an ideal world you're paying a fixed cost per unit time to pump the tube down then you shove as much stuff as you can through it at transsonic speed, catch it all with regenerative brakes at the other end, and pay an energy per kg payload cost lower than electric road vehicles.
Of course in practice that fixed cost may turn out astronomically high, but that's the idea.
Note the main way in which the JR Maglev will allow adding speed is by building a very straight line for a lot of money, which could benefit conventional rail just as well.
I guess the 18,000 packages per hour that arrive at ANC by jet must also be a matter of "face"?
What does this even mean?
Edit for clarity: The FedEx terminal at Ted Stevens Anchorage International Airport can handle 13,400 packages per hour. The UPS terminal there handles about 5,000 packages per hour. Virtually all of these packages arrive from Asia on jets traveling hundreds of miles per hour (as opposed to the alternative, container ships, which are cheaper, but much slower).
That's because Anchorage is the major airport that's closest to being on a great circle route between North America and Asia. Most of the packages clear customs in Anchorage, and are then fed into the FedEx and UPS systems for further distribution throughout North America.
Clearly there is a very large market for moving cargo at 500 miles per hour. Frankly, I have a hard time believing that an "expert in logistics" would make such a statement.
Alternatively, how much cargo does FedEx or UPS fly along the California coast?
But it does seem like saying instead of two rails that allow for deviations both horizontally and vertically and the vehicle stays on top, then now we need a really nicely round tube with a different set of requirements that must be maintained over hundreds or thousands of miles.
I guess if hyperloop teams are still in the phase of proving stuff out and they need money then the money they will get will still probably be tiny compared to what it would cost to actually build a real full blown system when you factor in all of the costs of buying land and permits and construction companies.
Hyperloop may be an unmitigated disaster. But the effort has clear benefits.
An innovative solution to shifting loads would be immediately useful to air freight, and probably trucking and shipping.
Some solution to the sudden loss of vacuum would be useful in everything from oil pipelines to freeway traffic. Turning the wall of air into a smooth gradient in seconds is perhaps impossible, but even a partial solution would create a whole host of companies to take advantage of the new technique.
New materials developed for the pylons, and techniques for manufacturing those pylons are likely broadly applicable. Bridges are of course an obvious example.
Does every flaw with the hyperloop require science fiction? Or is it just out of reach?
It seems like the Department of Transportation should provide a whole bunch of grad students money to answer the questions, rather than private investors, because those problems sound very big and very risky to me. But if they think they can do it, why not go for it?
The article makes some decent sounding criticism on the issue of last mile being the limiting factor. But it all reminds me of what I heard before regarding fast internet connectivity (the issue of the last mile), or why would people need personal computers. The problem with criticizing anything that can impact the future, is that we just don't know how it'll impact it.
I do know that anytime transportation or means of connecting goods or people has been changed, it has had tremendous impact in economy and how the world works.
Do we need to ship cargo at 500 MPH? With today's thinking, maybe no. But I do know by building and experimenting with Hyperloop not only we might just transform the world, in the process will probably make other accidental discoveries as an added bonus.
Is there an app that ensures I never read anything by this guy again? What is his name so I can avoid in the future?
I'm not saying Hyperloop is perfect...its the tone of this jerk.
$141M funding.
Fans inside of the tube would pull air in the direction of travel, and it could be circulated or pumped in from / out to the outside at the ends. At the end of the tubes a main fan system would be the primary work horse, creating vacuum forces on the arrival end and pushing forces on the departure end.
In the last mile, the fan system could shut down and use the pressure to help stop the vehicle and even store some of the pressure to help start the system in the opposite direction later (i.e., regenerative breaking).
Among other things it's more efficient to send electricity than to send air.
EDIT:
Wait, if the walls were made to be near frictionless, then the aggregate energy, minus what's lost to hear from turbulence, would be used for motion, right?
Am I thinking if this wrong?
I'm 91% sure that this is less to do with freight specifically and more to do with the amount of weight involved and how it's distributed in each car. Then again, I'm no expert on freight trains.
Especially since the current price of Helium is artificially low, and it's not a renewable resource at current extraction rates, so the price is not going to remain so low in the future.
EDIT: I found the song!: https://www.youtube.com/watch?v=ZDOI0cq6GZM